UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 18, 2004 TC PIPELINES, LP (Exact name of registrant as specified in its charter) DELAWARE 000-26091 52-2135448 (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number) Identification No.) 110 TURNPIKE ROAD, SUITE 203 WESTBOROUGH, MASSACHUSETTS 01581 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (508) 871-7046 NOT APPLICABLE (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: [ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) ITEM 8.01 OTHER EVENTS. TC PipeLines, LP owns a 30% general partner interest in Northern Border Pipeline Company. The remaining 70% is owned by Northern Border Partners, L.P., a publicly traded limited partnership. On November 17, 2004, Northern Border Partners, L.P. announced that ONEOK, Inc. had closed the purchase of two of Northern Border Partners' general partners, Northern Plains Natural Gas Company and Pan Border Gas Company. As a result of this purchase ONEOK, Inc. now owns 82.5% of the general partner interest and 500,000 common units of Northern Border Partners. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. TC PipeLines, LP By: TC PipeLines GP, Inc., its general partner Date: November 18, 2004 By: /s/ Russell K. Girling ----------------------- Russell K. Girling Chief Financial Officer